title: The sonopartogram: a novel method for recording progress of labor by ultrasound.
abstract: OBJECTIVE
  Progress of labor has hitherto been assessed by digital vaginal examination (VE). We introduce the concept of a non-intrusive ultrasound (US)-based assessment of labor progress (the 'sonopartogram') and investigate its feasibility for assessing cervical dilatation and fetal head descent and rotation.
  
  
  METHODS
  This was a prospective study performed in 20 women in the first stage of labor in two European maternity units. Almost simultaneous assessment of cervical dilatation and fetal head descent and rotation were made by US and digital VE.
  
  
  RESULTS
  The total number of paired US and digital VE assessments was 52, with a median of three per woman. Overall, 5% of sonopartogram parameters were not obtained compared with 18% of conventional digital VE parameters (P < 0.001). Assessment of cervical dilatation was possible in 86.5% of US examinations and 100% of digital VEs (P = 0.02), and dilatation was assessed as being greater by digital VE than by US (mean difference, 1.16 (95% limits of agreement, -0.76, 3.08) cm, r(2) = 0.68, P = 0.01). Fetal head descent was measured in all 52 cases by both methods (r(2) = 0.33, P < 0.001), but correlation between the two was only moderate. Head rotation was obtainable in 98% of US examinations and 46% of digital VEs (P < 0.001), with a mean difference of -3.9° (95% limits of agreement, -144.1°, 136.3°).
  
  
  CONCLUSIONS
  In this proof-of-concept study, the acquisition of data regarding progress of labor was more successful for the sonopartogram than the conventional partogram. The agreement between digital VE and US was good for cervical dilatation and head rotation but less so for head descent. US assessment of the progress of labor is feasible in most cases.
authors.affiliation: Fetal Medicine Department, Rosie Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.
authors.forename: W A
authors.initials: WA
authors.lastname: Hassan
authors.forename: T
authors.initials: T
authors.lastname: Eggebø
authors.forename: M
authors.initials: M
authors.lastname: Ferguson
authors.forename: A
authors.initials: A
authors.lastname: Gillett
authors.forename: J
authors.initials: J
authors.lastname: Studd
authors.forename: D
authors.initials: D
authors.lastname: Pasupathy
authors.forename: C C
authors.initials: CC
authors.lastname: Lees
mesh_terms: D000328:Adult; D005240:Feasibility Studies; D005260:Female; D058869:Gynecological Examination / Q000379:methods*; D006257:Head / Q000000981:diagnostic imaging; D006801:Humans; D007746:Labor Presentation; D007747:Labor Stage, First / Q000502:physiology*; D011247:Pregnancy; D011446:Prospective Studies; D015203:Reproducibility of Results; D016216:Ultrasonography, Prenatal / Q000379:methods*; D055815:Young Adult
keywords: intrapartum; partogram; transperineal